Variable ratio fluid transmission of the reciprocating piston type



Ap ,7, 1953 A. JARMANN, JR 2,633,710

Y VARIABLE RATIO FLUID TRANSMISSION OF THE RECIPROCATING PISTON TYPE 5Sheets-Sheet 1 Filed Aug. 1, 1947 Alfred Jarhvann, Jr.

W eon pm fiMe April 7, 1953 A. JARMANN, JR 2,633,710

VARIABLE RATIO FLUID TRANSMISSION OF THE RECIPROCATING PISTON TYPE 5Sheets-Sheet 2 Filed Aug. 1, 1947 Inventor Alfred Jarmann, Jr.

April 7, 1953 A. JARMAN N, JR 2,633,710

VARIABLE RATIO FLUID TRANSMISSION OF THE RECIPROCATING PISTON TYPE '5Sheets-Sheet 3 Filed Aug. 1, 1947 w M a m J r h A By QM wk .1 m9 m9 m: Eas l 9 K R w 5 WWW 7 Patented Apr. 7, 1953 VARIABLE RATIO FLUIDTRANSIMIS SIGN OF THE RECIPROCATING PISTON TYPE Alfred J armann, J r.,Schodack Landing, N. Y.

Application August 1, 1947, Serial No. 765,294

1 Claim. (CI. 60-53) This invention comprises novel and usefulimprovements in a variable fluid transmission and more specificallypertains to a hydraulic transmission mechanism for transmitting rotarymotion between a driving and driven member at predetermined and variablespeed ratios.

It is a primary purpose of this invention to provide a variable fluidtransmission which will be positive in operation, eliminating slippageand lost motion.

A further purpose of the invention is to provide a transmission inconformity with the fore going objects which shall be variable as to thespeed ratio as well as to the torque transmitted thereby.

Another object of the invention is to provide a mechanism in accordancewith the foregoing objects which shall be capable of operatingselectively in both forward and reverse directions, without changing thedirection of rotation of the driving member.

Yet another object of the invention is to provide a transmission inaccordance with the preceding objects which may be operated as anover-drive, indirect drive, in reverse and in variable speed ratioswithin these ranges.

Yet another intention of the invention is to provide a hydraulictransmission as set forth in the above mentioned objects which shall beequally applicable as a brake when employed in a vehicle or similarmechanism.

An additional purpose of the invention is to provide an appliance as setforth in the above objects which shall be capable of control by a singleadjusting lever for all of the above mentioned modes of operation.

Still another purpose of the invention is to provide a transmissionwhich is variable in conformity with the above mentioned objects andwhich shall have a simplified control means 1 And a very importantintention of the inventionis to provide a hydraulic transmission ascharacterized in the preceding objects which shall have in the directdrive position, with the drive shaft of the transmission a directconnection from the driving to the driven member through the medium ofcompressed oil, whereby there shall be no moving parts of thetransmission itself except its bearings.

And a final purpose of the invention to be specifically enumeratedherein resides in providing a transmission of the characteristics aboveenumerated which shall be compactly held in a unitary casing, ofrelatively few parts and yet capable of a wide range of adjustment,which shall be durable and dependable in its operation and withal ofinexpensive construction.

These, together with various anciliary objects of the invention whichwill later become apparent as the following description proceeds, areattained by this device, a preferred embodiment of which has beenillustrated, by way of example only, in the accompanying drawings,wherein:

Figure 1 is a fragmentary longitudinal sectional view showing theimproved transmission in accordance with this invention connected to adriving and driven member and is taken substantially upon the plane ofthe broken section line ll of Figure 6;

Figure 2 is a vertical transverse sectional view through the pistonconnecting means of the driving portion of the mechanism and is takensubstantially upon the plane of the section line 22 of Figure 1; 1

Figure 3 is a vertical transverse sectional view through the drivingcylinders of the mechanism and is taken substantially upon the plane ofthe section line 33 of Figure 1;

Figure 4 is a vertical transverse sectional view through the valvemechanism of the invention and is rotated substantially 90 from a viewtaken substantially upon the plane of the section line 4-4 of Figure 1;

Figure 5 is a view in vertical transverse section through the drivencylinder of the invention and rotated substantially 90 from a view takensubstantially upon the plane of the section line 5-5 of Figure 1;

Figure 6 is a vertical transverse sectional view taken through theadjusting means for varying the capacity of the driven member of thetrans mission and is taken substantially upon the plane of the sectionline 6-6 of Figure 1; and,

Figure '7 is a horizontalsectional elevation of a portion of 'theinvention taken substantially upon the plane of the section line 1-1 ofFigure 6.

Referring now more specifically to the accom panying drawings, whereinlike numerals designate similar parts throughout the various views,attention is directed first to Figure 1, wherein the invention isapplied to any suitable mechanism for converting motion from a drivingmember to a driven member, such as the transmission mechanism of anautomotive vehicle, although the invention is obviously applicable toany other environment employing a power transmitting means.

In accordance with the invention, the transmission casing, a portion ofwhich is shown at I0, is suitably mounted in any desired manner upon asupporting framework such as the chassis of a motor vehicle, not shown,and in this environment or use is suitably secured to the casing of theengine, not shown. The power is applied from a driving shaft l2 whichmay constitute a portion of the crank shaft of an engine, and to whichis secured as by fastening bolts l4, a portion of a flywheel l6. Secureddetachably to this latter element as by bolts [8, is the flangedextremity 20 of a generally hollow cylindrical housing 22 which isclosed at its other end and is rotatable with the flywheel I6.

At its open end, that is, the end portion bolted to the flywheel, thehousing '22is providedwith a cylindrical bore or chamber 24 whichtermim.

ates in a shouder or bottom wall 2%.

Extending through the closed .end .of the cylindrical casing 22 andaxially aligned with the bore 24, is a second bore 23 for a purpose tobe later set forth. Detachably and rigidly secured in the bore 24, is anannular or cylindrical block 3% which is provided with a plurality ofparallel bores 32 forming cylinders in the operating unit of thetransmission as will be set forth hereinafter, these cylinders beingparallel to each other and equidistantly spaced about the axis of theblock 30 and bore 24, and are provided upon the adjacent and innerportions with cut-away por tions 34 for a purpose to be later set forth.

A drive shaft .36 is disposed axially in the bores 24 and 2B, and at itsinner extremity is providedwith a reduced portion 38 which is journalledin anti-friction bearings 48 in the end of the crank shaft I2, while atits outer end, the shaft 35 has detachably secured thereto a drivingflange by which a connection may be made with any suitable driven shaft,this flange being indicated at 4 2 and secured upon the reducedextremity 44 of the shaft 36 as by a fastening bolt 56.

An axial bore 48 is provided in the block 35, and the sleeve-likeextremity B of an annular valve member 52 is journalled therein. Thisvalve member is provided with an annular rib 54 having sliding andsealing engagement with a-corresponding rib carried by the complementaryvalveinember 58, these two valve members bein seated between the abovementioned shoulder 25 and the inner extremity of the block 30, wherebythe valve is firmly but rotatably seated in the housing 22.

The two complementary sections of the valve member are provided with anannular outer channel 68 upon the outer periphery of the valve members,for a purpose to be later set forth. By means of keys or splines t2, thevalve section 52 is secured by its sleeve 5a in fixed and rigid positionupon the shaft 35, while the other valve section 58 is provided with arearwardly extending annular sleeve portion 6 1 which is journalled uponthe shaft 3% and is fixedly secured as by keys or splines as to thestationary casing it. Thus, the valve section 58 is rigidly secured tothe stationary casing It, while the valve section 52 is keyed to theshaft 36, for selective rotation therewith as set forth hereinafter.

The shaft 36 intermediate its ends and within the confines of the valvesections 52 and 58, is provided with an enlarged portion 68 and an annular chamber 78 is defined between this enlarged portion and the innersurfaces of the valve sections 52 and 58. As shown best in Figure 3, theblock Si) is secured in the bore 24 of the housing 22 by means of aplurality of pins i2 detachably fastening these parts together; althoughas will be readily appreciated the block 36 may in some instances beintegrally for-med with the housing 22.

Reciprocable in each of the cylinders 32, is an operating piston 14while similar pistons 16 are slidable within the cylinder '58 of theoperated portion of the transmission.

Referring now more specifically to Figures 1, 4 and 5, it will'be seenthat the annular chamber 60 is provided with arcuately extending portsand 82 communicating respectively with the operating and the operatedunit cylinders. Similarly, the inner chamber iii of the valve member isconheated by arcuate ports 84 and 85 with the chambers of the operatingand operated units. These ports are substantially semi-circular wherethey communicate withthe valve chambers, but are of such arcuate extentwhere they communicate with the cylinders that but one cylinder of eachunit can establish communication therewith at a time. Thus, as relativerotation of the valves and cylinders occurs, each cylinder issuccessively placed in communication with one or the other of thechannels 69 and it, while a corresponding cylinder of the other unit islikewise and simultaneously in registry therewith.

Referring now to Figures 1 and 2, it will be seen that the outerextremity of the shaft 36 is provided with splines or keys 92 by meansof which is fixedly secured a Wobbler plate 54 which if desired may bemore conveniently formed of a pair of sections as indicated, and whichis.

pressed against a suitable shouldered portion of the shaft andretainedthereon as by a threaded fastening nut. The Wobbler plate isprovided with a cylindrical surface upon its periphery which is inclinedrelative to the axis of the shaft 35, and which is provided with anannular groove or channel 95 within which is rotatably seated an annularring 98 having integral radially extending ball portions H30 thereon.

As shown, these ball members are integrally formed upon the ring 98, butif desiredmay be rigidly but detachably secured thereto in any.

suitable manner. Pivotally and slidably received upon the balls use areseat portions 162 consisting of sockets formed in the inner extremitiesof the pistons '14, and by means of which the pistons are reciprocatedin response to rotation of the ring 93 and vice versa. The cut-away portions 34, of the cylinders 32 obviously provide clearance for therelative angular movement and positioning of the Wobbler plate 34 duringrelative rotation of Wobbler and cylinders.

Referring now more specifically to Figures 1, 6 and 7, it will be seenthat the pistons E5 of the driven unit of the transmission are likewiseprovided at their outer extremities with seats or sockets I04 forswivelly and pivotally receiving ball members I05 rigidly or integrallycarried by the inner surface of a ring Hi8 which is rotatably receivedin a channel of a control yoke I69 forming a swash plate which ifdesired may for convenience by formed of two semi-circular halvesdetachably secured as by bolts l M. The control yoke is provided withtrunnions l 12 and H5 journalled in bosses He and H8 in the sides of thestationary casing I i) at diametrically opposite sides thereof relativeto the longitudinal axis of the shaft 33. The trunnion l is extendsexternally of the casin l0 and has a lever 126 secured ing an eyeportion I22 engageable by any suitable.

operating means, not shown, whether manual or automatic, is adjustableto a plurality of positions by means of which the inclination of theyoke;

may be'varied and the position of the pistons 16 in the cylinders i8.maybe adjusted. When the lever is in the position indicated at I22 inFigure 1, thecontrol yoke of the swash plate is at the same inclinationrelative to the-shaft 38;

as thatof the wobbler plate 94, and since the T bores of the cylinders32 and I6 and the diameters of the pistons I4 and 16 are all equal, itwill be evident that the pistons I4 and I6 thus have the samedisplacement in their cylinders. When moved to the position I24, thecontrol yoke is disposed perpendicular to the longitudinal axis of theshaft 36, whereby each of the pistons I6 is at the same position in thecylinder bores, and J consequently there is no relative movement ofthesepistons in their bores. Thus, when in this position, the transmission isin direct drive between the driving crank shaft I2 and the driven shaftattached to the coupling 42, with no move I ment of the transmissionparts other than the movement of the shaft 36 with its bearings. Whenmoved to the position indicated at I26, the transmission is in itsover-drive position which is the high speed ratio normally employed forthe predominant use of the device. Finally, the control yoke may bemoved to the extreme position indicated at I28, whereupon the shaftconnected to the coupling 421s driven in a reverse 1 direction comparedto the rotation of the driving shaft I2.

Obviously, variations of speed ratios between the positions I26 and I24,I24 and I22, and I22 to I28, are possible thus giving flexible operationto the transmission without the necessity of em} ploying gears. Theoperation of the mechanism is as follows, it being understood that thecrank shaft I2 throughout all positions of adjustment of thetransmission is rotating constantly in one direction, carrying with itthe flywheel I6, the

housing 22 and the block unit 39 therein, and

the pistons 14 together with the ring 98. In the neutral position, asshown at I22 in Figure 1, the rotation of the block 36 causes therotation of the ring 98 without the wobbler plate 94, therebyreciprocating the pistons I4. During part of their revolution, eachpiston I4 of the driving unit pumps fluid into the outer chamber 60 ofthe valve, and withdraws fluid from the inner chamber "I6 thereof.

tained in the chambers 60 and ID or in the cylinder bores 32 and 18.Thus, there is no tendency to rotate the shaft 36, and thereforealthough the crank shaft I2 rotates there is no torque Simultaneously,the rotation of thepiston I6, cylinder 18 and ring I08 of the drivenunit cause an identical but transmitted to the coupling 42 for rotatingdriven shaft.

When now the control lever is put in the posi-'- tion shown at I24,there is no displacement of the pistons I6 despite the rotation of thehousing 22 and of the pistons I6, since the pistons I6 and theirconnecting ring I08 slide freely in the control yoke. Consequently, thefluid delivered by th pistons I4 establishes a pressure which canrotateat the same speed as the crank shaft I2, the housing 22 and the pistonsI4 thereby establishing a direct drive between crank shaft I2 and thedriven shaft secured to the coupling mem ber 42.

Obviously, in positions between those shown at I22 and I 24, some of thefluid delivered by the piston I4 can now be displaced into the cylinderI8 in view of the adjusted reciprocation of pistons I6 by varying theinclination of the control yoke beyond the neutral position. Inproportion to this displacement, the wobbler plate 94 and shaft 36 arerotated at various speeds relative to the crank shaft I2, therebyestablishing variable speed ratios between the crank shaft I2 and thedriven shaft.

In the over-drive position indicated at I26, the inclination of thecontrol yoke and positions of the pistons I6 are such with respect tothe driving unit pistons that the shaft 36 and the driven shaft attachedto the coupling member 42 is caused to rotate at a speed greater thanthat of the crank shaft I2.

In the reverse position indicated at I28, the displacement of thedriving and driven units is so timed as to cause the shaft 36 to rotatein the opposite direction throughout a predetermined speed range inbetween the positions I22 and I28 as desired.

From the foregoing the manner of constructing and utilizing the devicewill be readily understood and further explanation is believed to beunnecessary.

Since numerous modifications will readily occur to those skilled in theart after a consideration of the foregoing specification andaccompanying drawings, it is not intended to limit the invention to theexact construction shown and described, but all suitable modificationsand equivalents may be resorted to falling within the scope of theappended claim.

What is claimed as new is as follows:

A variable transmission com-prising a support, a fly-wheel, a driveshaft non-rotatably attached to said fly-wheel, a cylindrical housinghaving one end thereof secured to said fiy-wheel axially of said driveshaft, an end wall on the other end of said housing having a first setof circumferentially spaced cylinders therein, a driven shaft rotatablyjournaled in said fly wheel and extending through said end wall, anannular cylinder block having a second set of circumferentially spacedcylinders therein nonrotatably mounted within said housing adjaja-centsaid fly-wheel, first and second relatively rotatable valves rotatablymounted in said housing between said end wall and said cylinder blockselectively communicating the cylinders of the first set to thecylinders of the second set, pistons in said cylinders, a wobbler platecarried by said driven shaft operatively engaging the pistons in saidsecond set of cylinders, a swash plate movably mounted on said supportand operatively engaging said pistons in said first set e1 cylinders,each of, said valve memhere including an annular outer bearing surfacerotatably engaging the inner surface of said housing, the outer bearingsurface .of said first and second valves respectively abutting said endwall and the registering face of said cylinder block, an inner bearingsurface on each of said valves disposed radially inwardly from saidouter bearing surfaces, said inner bearing surfaces contacting eachother, said inner bearing surfaces and said housing defining an outervalve chamber, said inner bearing surfaces and said driven shaftdefining an inner valve chamber, parts in each of said valvesselectively each communicating one of the adjacent cylinders with saidouter chamber and .a second adjacent cylinder with said inner chamber.

, ALFRED JARMANN, JR.

8 REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,141,166 Bischof Dec. 27, 19382,151,415 Bennetch Mar. 21, 1939 2,486,690 'I'ipton Nov. 1, 1949 FOREIGNPATENTS Number Country Date 10,108 Great Britain Apr. 28, 1909 508,434France July 24, 1.920

